Question

When a system is taken from state \(i\) to a state \(f\) along path \(𝑖𝑎𝑓\), \(Q=50~J\) and \(W=20~J\). Along path \(ibf\), \(Q=35~J\). If \(W=-13~J\) for the curved return path \(fi\), \(Q\) for this path is

Answer 1

Formula used: \(Q=\Delta U+W\)
Given,
For path \(iaf,\)
\(Q=50~J\), \(W=20~J\)
For path \(ibf\)
\(Q=50~J\), \(W=-13~J\)
\(\Delta U\) remains same for both paths,
\(\Delta U_A=\Delta U_B\)

For path \(iaf\):
From the First law of thermodynamics,
\(\Delta U=Q-W=50-20=30~J\)

For path \(fi:\Delta U=-30~J\) and \(W=-13~J\)
\(\Rightarrow Q=\Delta U-W=-30-13=-43~J\)

Final Answer: (d)